At Westlake, Newnan jumped out to an 8-0 lead behind Martin, who struck out nine before hitting a speed bump in the fourth.
Johnson entered to quash the rally before proceeded to retire Westlake’s side in order in the fifth in what head coach Marc Gilmore called “the turning point of the game.”
“He threw up a zero and we scored after that to gain momentum back,” Gilmore added of Johnston.
Ahead 8-4, Newnan added more insurance with a run in the sixth and four more in the seventh on a rally that began with a leadoff triple by freshman Jett Lovett.
Junior Thomas Collins and seniors Everett Davis and Jay Cash had RBI hits in the final rally.
O’Neal closed the door on the Lions, striking out four in 1 2/3 innings to complete a two-game sweep of Westlake.
Newnan jumped ahead early on Lions starter Jaden Harden with a successful double-steal with two outs in the first, then set the table in the second on leadoff hits by Cash and Tucker Barnett to push ahead 5-0.
Michael Maginnis’s RBI single highlighted a three-run third after Westlake walked the bases loaded.
Davis finished with team-highs of three hits and three RBis among four Cougars that had multi-hit games. Austin Roberts, Cash and Collins each had a a pair with Collins finishing with 2 RBIs and two walks.
Maginnis and Lovett also had a hit and eyed two of Westlake’s 10 walks allowed.